In digital video systems such as a digital TV system, different incoming video images may have very different characteristics depending on the video format and the original video source. Some images may contain many high frequency components, indicating large amount of fine details or sharp edges. Other images may contain fewer high frequency components, and appear relatively smooth. Some video images in a high definition format may be generated by conversion from a standard definition video source. While other digital video images may be generated from an analog video source. Therefore, different video images may be quite different in terms of their signal frequency range and frequency distribution.
Image detail enhancement has been a continuing research topic. However, providing a good detail enhancement system that is suitable for different types of digital video images mentioned above, remains to be addressed by conventional solutions.